The present invention relates to an optical fiber unit and an optical fiber cable.
Techniques are known for forming an optical fiber cable including optical fiber units which are optical fiber aggregates formed by bundling a plurality of optical fibers. In such techniques, it is common to employ a method wherein a rough winding string (bundling member) is wound around the bundle of optical fibers to thereby suppress/prevent the bundle of optical fibers from falling apart while allowing the optical fiber units to be differentiated from one another by the colors of the bundling members.
In relation to such bundling members, particularly FIG. 7 of Patent Literature 1 discloses a technique wherein the circumference of a bundle of a plurality of optical fibers is bundled with two bundling members by winding the two bundling members in an S-Z configuration, and the two bundling members are bonded and fixed together at sections where their winding directions are reversed. Further, Patent Literature 2 discloses a technique wherein three or more bundling members are provided to bundle a plurality of optical fibers, and a first bundling member is joined to a second bundling member at a contact point where it contacts the second bundling member, and is joined to a third bundling member at a contact point where it contacts the third bundling member, and a winding direction of a bundle of optical fibers is reversed at the contact point to the second bundling member and the contact point to the third bundling member.